OK guys, I need some help on this. Vehicle is a 2006 G35 6MT, AEM cold air intake installed by PO. For a long time the vehicle had not liked driving in the rain. In really wet weather, it hesitates and stalls HARD. Like someone is dropping a hammer head in the cylinder. It's only intermittent, and it only happens in heavy rain. The vehicle is generally garaged, overnight, but occasionally sits out in the rain at work. Sometimes when it sits in very hard rain there is a puddle on the passenger side floor mat (I have rubber mats that collect the water).

This most recent time, weather had been rainy all day at work, I came out to a puddle on my passenger floor mat. Dumped out the water, started the interstate drive home. On the interstate, the car started stumbling and hesitating badly again. Doesn't go above 2000eRPM, doesn't rev. Car actually stalled on the interstate, and I rolled to the side. Eventually got it to restart and stay running long enough to pull under the bridge, where I sat KOEO with the fan blowers running full speed. Opened the hood, poked around, couldn't find anything significant. AEM cold air filter didn't look any more wet than I would expect. Eventually, got the car to start again, and let it sit and sputter and surge at idle until it ran smoothly enough that I could limp it home. The car ran pig-rich this whole time, exhaust gas was thick and visible compared to normal. I ripped off the trim on the passenger side and the module behind that kick panel was wet. I can't seem to figure out what that controller is, but it doesn't look big enough to be the engine controller.

Next day I had the codes pulled:
p0102 - Mass air flow sensor circuit low input
p0506 - The idle speed is less than the target idle speed by 100 rpm or more.

Both troubleshooting procedures suggest "intake leak", but I'm not buying it. Why would it only happen in wet weather? Anybody else have this concern?

 

i am reviving this , I have exact same problem now, what happened? Anyone ever figure anything out?

 

MAF was getting wet due to my Injen CAI. I took out the section of the tube that put the cone filter down by the fender such that now the filter is up behind the headlight. I also installed a water sock over the filter. No problems since.

 

Bumping my own thread for new ideas. This problem largely went away, but happened again during a hard rain in Houston this weekend. Exact same behavior. Drove though a puddle, car stalled. Eventually got it sputtering again enough to limp it to a parking spot to leave it for the weekend. When I came back it ran a little rough at first, but fine after a couple minutes of plugging back in the maf (I disconnected it to limp it to a parking spot). Anyone have any more ideas to make this car more, uhhh, water resistant?